This relates generally to imaging systems and, more particularly, to imaging systems with high performance pixels.
Modern electronic devices such as cellular telephones, cameras, and computers often use digital image sensors. Imager sensors (sometimes referred to as imagers) may be formed from a two-dimensional array of image sensing pixels. Each pixel includes a photosensitive layer that receives incident photons (light) and converts the photons into electrical charge. Image sensors are sometimes designed to provide images to electronic devices using a Joint Photographic Experts Group (JPEG) format.
In certain applications, pixels may be used to sense both visual and near infrared (NIR) light. However, NIR light may travel deep into the photosensitive layer before being converted into electrical charge. Therefore, in these applications it is desirable for photon-generated charge absorption in a pixel to be as deep as possible. Conventional methods of forming photosensitive layers include implanting ions into semiconductor material. However, there is a limit to how deep ions may be implanted. Ion implantation may therefore not produce photosensitive layers optimal for near infrared light sensing.
It would therefore be desirable to provide improved pixels for improved sensing of both visual and near infrared light.